Hi Stefan,
On Thu, Aug 27, 2020 at 11:49:34AM +0200, Stefan Wahren wrote:
Am 27.08.20 um 06:35 schrieb Hoegeun Kwon:
Hi Stefan,
Thank you for your review.
On 8/26/20 7:04 PM, Stefan Wahren wrote:
Hi Hoeguen,
Am 21.08.20 um 09:10 schrieb Hoegeun Kwon:
There is a problem that the output does not work at a resolution exceeding FHD. To solve this, we need to adjust the bvb clock at a resolution exceeding FHD.
this patch introduces a mandatory clock, please update brcm,bcm2835-hdmi.yaml first.
Is this clock physically available on BCM283x or only on BCM2711?
As far as I know, BCM2711 raspberry pi 4 supports 4k,
don't supported on pi 3 and pi 3+.
Since 4k is not supported in versions prior to Raspberry Pi 4,
I don't think we need to modify the bvb clock.
So I think it is better to update 'brcm,bcm2711-hdmi.yaml'
instead of 'brcm,bcm2835-hdmi.yaml'.
You are correct please update only brcm,bcm2711-hdmi.yaml.
My concern was that the function vc4_hdmi_encoder_pre_crtc_configure() is called on a non-bcm2711 platform or on a Raspberry Pi 4 with an older DTB. So making the BVB clock optional might be better?
It won't cause any issue on a non-RPi4 platform since the clock pointer will be NULL and clk_set_rate can deal with NULL pointers just fine: https://elixir.bootlin.com/linux/latest/source/drivers/clk/clk.c#L2221
For the older DTBs, it shouldn't be an issue either. We haven't merged the binding yet, so we don't have an upstream DTB using it
Maxime